Sonic Port Not Working Reliably

the first time i used the sonic port it worked fine... but the second and third times i tried using it i would get "not recognized" errors.

when it was recognized on occasion, the signal level of the guitar/line out was so low that it was unusable.

also from my understanding, a line level signal and an instrument level signal are two very different types of signal. how is the 1/4" output on the top of the sonic port both a guitar out and a line out at the same time? and how is it mono and stereo?